4.2.14 alpha build 7542

This update includes upgraded AV1 (*.avif) support (both opening and saving, and not just on Win10) thanks to the bundling of @null54‘s AvifFileType plugin. Performance and memory usage are improved, particularly when working with large images. Saving large, indexed (8-bit or less) image has been fixed, as well as the palette generation for 4-bit images (which was broken).

To get this update, make sure you have "Also check for pre-release (beta) versions" enabled in Settings, and then click on the Check Now button. (Unfortunately alpha/beta releases are not currently available for the Microsoft Store version of the app).


You can also download and install this update directly from the forum.

Changes since 4.2.13:

  • New: AV1 (*.avif) images can now be saved (not just opened), due to bundling of @null54‘s AvifFileType plugin (v1.0.4.0). Installation of Microsoft’s codec from the Microsoft Store is no longer necessary, which means this also works on Windows 7 and 8.1.
  • Improved performance in the canvas rendering engine, especially when working with large images, and most notably when scrolling and zooming
  • Reduced memory usage when working with images that have regions of solid color
  • Fixed an issue where saving an image at 4-bit color depth (usually pixel art) was using an incorrect palette (reduced color count/quality). This was due to a bug in Windows Imaging Component (WIC).
  • Fixed an issue where very large images (e.g. 50000 x 50000 px) couldn’t be saved at indexed bit-depths (8-bit or less) due to a bug in Windows Imaging Component (WIC). More information on the forum:
  • Fixed an issue where BMP images couldn’t be loaded if they had the .PNG extension (there’s an Android screenshot utility out there which does this …)
  • Fixed a rare crash in the Gradient tool ("The tool must be in the Drawing state …")
  • New: Added a list of the DLLs that are loaded into the process on the Settings → Diagnostics page. This is to help troubleshooting scenarios.

10 thoughts on “ 4.2.14 alpha build 7542

  1. D. Simmons says:

    Cannot update. Repeatedly getting “There was an error decompressing the download.”

  2. darthvitrial says:

    Did you find a workaround for the WIC bug or did Microsoft fix the bug?
    (If they fixed the bug I guess it would apply to older PDN versions too)

    • Rick Brewster says:

      I implemented workarounds.

      For the palette generation bug, whereby WIC can’t handle generating a palette for a large image (larger than about 2.6 GB of pixel data), I ask WIC to generate a palette from scaled-down version of the image. I use nearest neighbor sampling to ensure colors don’t get changed, although this does introduce the problem that some colors may be missed. Especially if there is a very regular grid/stipple pattern in the image.

      There are actually 2 bugs in WIC’s code path here that I had to dodge. The first is an arithmetic overflow that it catches and returns as a failure HRESULT (translated to a managed exception). The other is actually a divide by zero! It comes as an SEH exception, WIC doesn’t handle it, and it results in a memory leak. So I have to resize the image to less than about 1.7 GB to dodge this.

  3. LaaZa says:

    Saving AVIF at 100% quality produces corrupted colours, any lower quality works normally. Other settings don’t matter. Loading corrupted image in makes it look normal again but other decoders show it with corrupted colours.

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